#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl
#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)
template<typename T>
void amin(T &a, T b) {
a = min(a,b);
}
template<typename T>
void amax(T &a, T b) {
a = max(a,b);
}
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif
/*
read the solution a long time ago and remember some ideas from there
*/
const int MOD = 998244353;
const int N = 20 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;
vector<pii> adj[N];
void solve(int test_case)
{
int n,m; cin >> n >> m;
rep1(i,m){
int u,v; cin >> u >> v;
u--, v--;
adj[u].pb({v,0}), adj[v].pb({u,1});
}
map<int,int> dp[1<<n];
dp[0][0] = 1;
rep(mask,1<<n){
ll unset = ((1<<n)-1)^mask;
for(auto [bad,x] : dp[mask]){
rep(u,n){
if(mask&(1<<u) or bad&(1<<u)) conts;
int mask2 = mask|(1<<u);
int bad2 = bad;
bad2 |= (1<<u)-1;
bad2 &= unset;
for(auto [v,t] : adj[u]){
if(mask&(1<<v)) conts;
if(bad2&(1<<v)){
bad2 ^= (1<<v);
}
}
dp[mask2][bad2] += x;
dp[mask2][bad2] %= MOD;
}
}
}
ll ans = dp[(1<<n)-1][0];
ans = ans*m%MOD*((MOD+1)/2)%MOD;
cout << ans << endl;
}
int main()
{
fastio;
int t = 1;
// cin >> t;
rep1(i, t) {
solve(i);
}
return 0;
}
